It is reported that a phosphine ligand having a sterically complicated structure is useful for various transition metal-catalyzed reactions such as cross-coupling and investigations on synthesis of phosphine compounds have been addressed as a most important issue at home and abroad (for example, Patent Documents 1 to 3) and have drawn attention as an important approach to develop a highly practical catalytic organic transformation process.
Patent Document 1: JP 2001-253889 A
Patent Document 2: JP 2003-292498 A
Patent Document 3: JP 2003-313194 A